The present investigation was aimed to phytosynthesize silver nanoparticles (AgNPs) by utilizing aqueous extract of Mentha longifolia branches to reduce mass Ag into Ag° and evaluation of their potential to treat HCT116 colon cancer, Leishmanial, and bacterial cells. A characteristic Surface Plasmon Resonance (SPR) band to confirm synthesis was observed at ~ 450 nm of λ light by UV–Visible spectrophotometer. SEM and AFM micrographs unraveled that nanostructures are anisotropic, spherical and have a size under ~ 100 nm. Particle size analysis confirmed that the majority of the nanoparticles exist in ~ 6–20 nm of the size range. EDX investigation represented the highest peak of Ag with ~ 74% signal intensity. FTIR analysis confirmed the presence of the N–H (amine) group, C–N (cyanide) group and C≡C (alkynes) stretch as the surface capping agents. AgNPs were found biocompatible against human RBCs at a lower dose and LD₁₀₀ was recorded as 117 μg/ml, which shows that a very high dose of AgNPs is required to cause toxicity to RBCs. The selective dose-dependent response of AgNPs was reported against Leishmania tropica and decreasing the dose of the nanoparticles resulted in increasing the survival rate of the pathogen (P < 0.05);10 μg/ml of AgNPs killed practically 67% of cells. Antibacterial action against plant bacterial pathogens was seen between 2 and 12 μg/ml. Annexin V apoptosis analysis and SRB examination showed that the plant aqueous extract and AgNPs are incapable to control the development of HCT116 colon cancer cells and only 3.77% cells indicated apoptosis. The results show the biocompatibility of phyto-functionalized nano-silver to selectively treat Leishmania and plant bacterial pathogens.

本研究旨在通过利用薄荷叶分支的水性提取物将Ag的质量减少到Ag°中来植物合成银纳米颗粒（AgNPs），并评估其治疗HCT116结肠癌，利什曼原虫和细菌细胞的潜力。在λ的〜450 nm处观察到特征性的表面等离子体共振（SPR）谱带，以确认合成紫外可见分光光度计。SEM和AFM显微照片揭示出纳米结构是各向异性的球形，尺寸小于100 nm。粒度分析证实，大多数纳米颗粒存在于约6–20 nm的粒度范围内。EDX研究代表了具有约74％信号强度的Ag的最高峰。FTIR分析证实存在N–H（胺）基团，C–N（氰化物）基团和C≡C（炔烃）延伸基团作为表面覆盖剂。发现AgNPs在较低剂量下与人RBC具有生物相容性，记录的LD ₁₀₀为117μg/ ml，这表明需要非常高剂量的AgNPs才能对RBC产生毒性。据报道，AgNPs对热带利什曼原虫有选择性的剂量依赖性反应降低纳米粒子的剂量可以提高病原体的存活率（P  <0.05）； 10μg/ ml的AgNPs几乎杀死了67％的细胞。观察到对植物细菌病原体的抗菌作用为2至12μg/ ml。Annexin V凋亡分析和SRB检查表明，植物水提取物和AgNPs无法控制HCT116结肠癌细胞的发育，只有3.77％的细胞显示凋亡。结果表明，植物功能化的纳米银具有生物相容性，可选择性治疗利什曼原虫和植物细菌病原体。